Control equipment for prime mover electric generating plants



H. BANY 2,363,850 I CONTROL EQUIPMENT FOR PRIME MOVER ELECTRICy GENERATING PLANTS Nov. 28, 1944.

Filed Nov. 22, 1941 2 Sheets-Sheet 1 uw .wm ma r .CBO wm Va .mm H9 .7m

H. BANY Nov. 28, 1944.

CONTROL EQUIPMENT FOR PRIME MOVER ELECTRIC GENERATING PLANTS Filed Nov. 22, 1941 2 Sheets-Sheet 2 lrwc-z-'wlor` Herman Bang,

His Attorney wrm@ Patented Nov. 28, 1944 FFICE CONTROL EQUIPMENT FOR PRIME MOVER ELECTRIC GENERATING PLANTS Herman. Bany, Lansdowne, Pa., assignor to YGleneral Electric Company, a corporation of New York Application November 22, 1941,- SerialNo. 420,148

, 9 Claims.

My invention relates to control equipments for prime mover electric generating plants and par- 34 and causes the member 8 t'o be moved downwardly against the bias of an opening spring l2 ticularly to an equipment for controlling the operation of a plant comprising an alternating current. synchronous generator driven by a fluid operated prime mover such as a. wind turbine, the propeller of which is driven by a fluid the velocity of which varies over a Wide range.

One; object ofl my invention, is to provide an improved control equipment for starti-ng up such a plant when the velocity of the -uid driving the prime mover is sufficient to cause the plantI tot generate aI predetermined amount of electric power, for limi-ting the power output of the plant when the velocity of the fluid driving kthe* prime mover is in excess of a predetermined amount, for temporarily shutting; down the plant under certain. abnormalE .conditions such as when the velocity ofy the fluid isy above. a predetermined maximum value and also. when it decreases to a valuefwhichis' not suiflcient to' cause the plant to' generate a predetermined amount of electric power, and for shutting down the plant completely under certain other emergency conditions such, for example, as when the turbine speed exceeds a. predetermined value or the generator falls outV of synchronism.

My invention will be better understood from the following description when taken in connection with the accompanying drawings, Figs. 1 and 2 of which when combined by placing Fig'. 1 above. Fig. 2 diagrammati'cally illustrate av control arrangement for a wind turbine-driven alternating current generator, and the scope of my invention, which is embodied' in the disclosed control arrangement, will' be pointed out in the appended. claims.

Referring. to theY drawings, I represents a prime mover dynamo-electric plantcomprising an. al'- terna-ting current generator 2 driven by a wind turbine 3. The. turbine 3 includes a propeller 4 and suitable mechanism 5 associated therewith for varying the angle of the propeller blades. This bladev angle adjusting mechanism 5, which may be of anyv suitable construction, examples of which are. well known in theY art, is controlled by means of a speed governor E which includes the; yballs 'l driven in any suitable manner at at-'spee'd' proportional. to the speed of the propeller-4. The yballs 1 operate against the tension of an' adjustable spring 1'.. The position of until it engages a stopl3.l When the movable member' 8 is in this position, which is known as the shut down position of the governor 6, the operating member i8 is operated by the fluid motor 9 so that the blades of the propeller A are in their feathered or 90` position in which position the available Wind has its minimum effect upon the propeller. Associated with the operating member I are the position switches l4-I8, inclusive, which are respectively closed during different ranges of blade angles. For example, in the particular embodiment shown, it is assumed that the switch il is closed when the blade angle is and above; the switch I5 is closed. whenA the blade angle is 9 and above; the switch I6 is closed. when the blade angle is 28 andabove; the switch l1 is closed when the blade angle is 32 and below; and theswitch I-8' is closed when the blade angle is 90 and above.

When. the magnet lil is. energized, the position of the movable member 8 is determined by the position of either the fiyballs l or a cam which is operated by means of a reversible motor 2|. Theposition of the il-yballs 'l for any given speed of the turbine 3 may be' varied. by adjusting the tension of the spring l by operatingv a reversible motor 22. Associated withv the spring I are the position switches 234B, inclusive, which are respectively arranged to be operated when the spring T is adjusted tov cause the yba'lls 'l to maintain a predetermined' speed. For example, in the particular embodiment shown, it is. assumed that' the position switch 23 is closed when the spring 1 is adjusted to, or above, its 50% 'speed' no load position. The position switch 24 is closed when the spring 1" is adjusted to, or above, its speed no load position; the position switch 25 is closed when thel spring 1 is adjusted to, or above, its speed no load position;` and the position switch 26 is closed when the spring T is adjusted. t0, or above, its 100%v speed full load position.

, Associated with the motor-operated cam 20 fare-the position switches 28-33, inclusive, which are respectively closed when the cam 20 is in certain. positions to effect predetermined propeller blade angles. For. exampla-in the particular embodiment shown, it is assumed that the position switch 28 is closed when the cam 2.0 is in a' position to effect a blade angle of more than 59'; theposition'. switch. 23 is closed when the cam 2.02 is inV a positionV toy eie'cta blade angleL of 5 or less;v the position switch 30. is closedI When the cam- 20- is in a position toeiecta blade angle of more than 30";v the position switch 3l is closed when the cam 20 is ina position to effect a blade angle' of less than 30; the position switch 32 is closed when the cam 20 is in a position to effect a blade angle of 90, or more; and the position switch 33 is closed when the cam 20 is in a position to effect a blade angle of less than 90.

When the plant I is shut down, the magnet il is deenergized so that the movable member 8 is moved to its shut down position by the closing spring 34, and the propeller blades are moved to their feathered or 90 position. During the normal operation, however, of the plant, the magnet II is energized so that the ,position of the movable member 8 depends upon the position of either the ilyballs 1 or the cam 28 depending upon which is in a position to effect the larger blade angle. Y

As shown in the drawings, the governor mechanism is in the position it occupies after the plant I has been shut down due to awind velocity of too small a value to operate the plant at a predetermined load. Under such conditions, the spring 1 is adjusted to between its 90% speed no load position and its 100% speed full load position, and the cam 20 is in a position to produce a predetermined blade angle such,ffor example, as 30, which is a less efficient angle than the most efficient blade angle which, for the purpose of this description, is assumed to be When the wind velocity increases to a suflicient value to operate the plant at a predetermined load, the speed of the turbine 3 increases to a sufficient value to operate a speed responsive switch 3B, while the propeller blades are set at a 30 angle, and thereby complete an energizing circuit for a time relay 31 which, after being energized for a predetermined time, completes an energizing circuit for an associated control relay 38 if at the same time the voltage of the alternating current system 48, to which the generator 2 is to supply current, is suiicient to eiect the operation of an associated voltage relay 61, The relay 38, when energized, completes an energizing circuit for the cam motor 2| so that the cam 20 is slowly moved from its 30 position to its 5"V position in which position the cam position switch 28 is open, and the cam position switch 29 is closed. This change in the position of the cam changes the position of the movable member 8 of the governor mechanisrn 6 so that the propeller blade yangle is correspondingly decreased to a more efficient value and thereby causes the available wind to increase the speed of the turbine 3. When the turbine speed increases above a predetermined value, the voltage of a direct connected exciter 39 causes an exciter voltage relay 40, which is connected across the terminal of the exciter 39, to pick up and complete an energizing circuit for a time relay 4I if at the same time the spring 1' is adjusted to, or above, its 90% speed no load position so that the governor spring position switch 24 is closed, the cam 20 is in its 5 blade angle position so that the cam position switch 29 is closed and the actual blade angle is between 9 and 32 so that both of the blade angle position switches I5 and I1 are simultaneously closed.

After being energized for a predetermined time, the relay 4I completes an energizing circuit for a master relay 42 which, in turn, completes an energizing circuit for the operating winding 43 of a field switch 44 so that the field winding 45 of the generator 2 is connected across the terminals of the exciter 39. The closing of the field switch 44 also effects the energization of an associated control relay 46 as long as the circuit breaker 41, which is arranged to connect the generator 2 to the electric system 48, is open.

The control relay 46 completes an energizing circuit for a synchronizing control relay 49 which, when energized, connects across the l terminals of the generator 2 and the energized the generator 2 is higher than the frequency of the system 48; the contacts 52 are closed when the frequency of the generator 2 is lower than the frequency of the system 48; and the contacts 53 and 54 are simultaneously closed when the frequencies of the generator 2 and of the system 48 are the same. The closing of the contacts 5I completes an energizing circuit for the spring'adjusting motor 22 so that the spring 1 is adjusted to cause the lyballs 1 to hold a lower speed whereas the closing of the contacts 52 completes an energizing circuit for the motor 22 so that the spring 1' is adjusted to cause the flyballs 1 to hold a higher speed. When both of the contacts 53 and 54 are simultaneously closed,

an energizing circuit is completed for a time relay 55 which renders operative an automatic synchronizer 56 of any suitable type so that it closes its contacts 51 when a predetermined phase relation exists between the voltages of the generator 2 and the system 48. The closing of the contacts 51 completes an energizing circuit for an associated control relay 58 which, in turn, completes an energizing circuit for the closing coil 59 of the circuit breaker 41 so that the generator 2 is connected to the system 48. The closing of the circuit breaker 41 also effects the deenergization of the control relays 46 and `49 so that the differential frequency responsive means 58 and the automatic synchronizer 56 are rendered inoperative. The closing of the circuit breaker 41 also effects the completion of an energizing circuit for the governor spring adjusting motor 22 so that the spring 1' is adjusted to cause the flyballs 1 to maintain a higher speed and thereby effect a decrease in the angle of the propeller blades and an increase in the output of the plant I.

The output of the plant I is limited either by the power output of the generator 2 exceeding a predetermined value so that a power relay 60, which is connected so as to be responsive to the power output of the generator 2, opens its contacts 81, or by the blade angle of the propeller 4 being decreased to its minimum or most eliicient angle, which is assumed to be 5, so that the blade angle position switch I4 is opened.

During the normal operating range of wind velocities, such for example as the range between 30 and 60 miles per hour, the output of the plant I is controlled by the power relay 60 which is so arranged as to effect a decrease in the blade angle if the power output tends to decrease below a predetermined value and to effect an increase in the blade angle if the power output tends to increase above this predetermined value, It will be evident that, as the wind velocity increases, the governor 6 causes the blade angle to increase and as the Wind Velocity decreases, the governor B causes the blade angle to decrease. When the wind Velocity exceeds a predetermined high value, such for example as 60 miles per hour, the blade angle increases to 28 or above so that the blade angle position switch I6 is closed and thereby lpredetermined minimum value.

completes an energizing circuit for a time relay 62; After being energized for a predetermined time, the relay 62 completesv an energizing circuit for a control relay 63, which establishes independently of the position ofthe power relay 60, an energizing circuit for the governor spring adjusting motor 22 'so that the spring 1 is adjusted to causethe governor 6 to increase the blade angle and thereby decrease the power output of the plant I until rthe power output decreases below a Thena second power relay 65, which is connected so as to close its contacts whenever the power output of the generator 2 is Vbelow this predetermined minimum value, effects, by means of an associated control relay v|36, the deenergization of the master relay 4. The relay 4, by opening its contacts, effects the opening of the circuit breaker 41 and the eld switch 44.

The decrease in load on the prime mover effected by the operation of the governor spring adjusting motor 22 and the opening of the circuit breaker 41 causes the governor A6 to effect 'an increase in the blade angle so that it exceeds 32. Therefore, as long as the wind velocity remains above a -predetermined high value at no load, the blade angle position switch I1, which is v in the energizing circuit of the relay 4|, remains open. When, however, the wind velocity at no load decreases so that the governor reduces the blade 'angle below 32 and thereby causes the lade angle position switch I1 to close, an energizing circuit is completed for the time relay 4| which, after being energized for a predetermined time, completes an energizing circuit for the master relay 4. The differential frequency responsive means 50 and the automatic frequency syncronizer 56 then are rendered operative in the manner heretofore described to effect the automatic synchronization of the generator 2 with the system 48.

When the wind velocity decreases to such a low value that the governor 6 causes the blade angle to be reduced to the blade angle position lswitch |4, which is in the circuit of the motor 22, is opened to prevent a further increase in the loadsetting of the spring 1. Therefore, if the wind velocity continues to decrease after the switch I4 is opened, a'corresponding decrease in the power output of the plant I occurs until at apredetermined low wind velocity, the power relay 65 operates to effect the deenergization of the master relay 42 and the opening of the circuit breaker 41 and the held switch 44 iny the manner heretofore described. When the wind velocity again increases to a sufficient value to cause the flyballs 1 to effect an increase in the blade angle above 9 so that the blade angle position switch I5 is closed, thetiine relay 4I is again energized to effect another automatic connection of the generator 2 to the system 48.

If, while the plant I is in operation, the voltage of the system 48 decreases below a predetermined value so that the voltage relay 61 returns to its deenergized position or the generator 2 falls out of "step for any reason so that the contacts of an associated out-'of-step relay 64 are closed, the relay 38 'becomes' deenergized and effects the deenergization of the master relay 42 and the 4opening of the circuit breaker 41 and the field switch 44. If the undervoltage relay 61 is the cause of the relay 38 becoming deenergized, a Vcircuit iscompleted for the cam motor 2| to cause the cam 2|)` to be run toits 30 position when "the cam position switch 3| is open. A circuit in which position the cam position switch 32 is also completed for the motor 22 so that it adjusts the spring f1 to its 100% speed no load position as determined by its position switch 25. If, however, the out-of-step relay 64 is the cause of the relay 38 becoming deenergized, the motor 22 is operated to adjust the spring 1 to its 100% speed no load position, but the motor 2| is not operated to cause the cam 20 to be moved to its 30 position because the relay 38, which controls the operating circuit of the motor 2 I, is reenergized as soon as the circuit breaker 41 opens,

In order to effect an emergency shut down of the plant I under certain emergency conditions, a lock-out relay 68 is provided. This relay ,is arranged to' be energized in response to the closing of the contacts 69 of suitable protective devices, not shown, which are arranged to be operated in response to predetermined abnormal conditions of the plant. Preferably the lock-out relay 68 is of the type which has to be manually reset after each energization thereof. The operation of the lock-out relay 68 effects the immediate opening of the circuit breaker 41. As soon as the circuit breaker 41 opens under such conditions, an ,energizing circuit is completed for a control relay 10 which immediately completes an energizing circuit for an associated control relay 1|, and which, after a predetermined time interval, completes an energizing circuit for another associated control relay 12. The relay 1I, when energized, completes an energizing circuit for the Spring-adjusting motor 22 so that the spring 1 is adjusted to its 50% speed no load position. The relay 12, when energized, effects the deenergization of the governor magnet II so that the closing spring 34 moves the movable member 8 to its shut down position thereby causing the propeller blades to be adjusted to their feathered, or position at which time the blade angle position switch I8 is closed to complete an energizing circuit for a control relay 14. The relay 12, when energized, also effects` the operation of the cam motor 2| so that the cam 20 is also moved to its 90 position 1s closed to complete an energizing circuit for a control relay 15. n

After the plant I has been shut down due to the occurrence of an emergency condition, the lock-out relay 68 may be reset manually at any time before the completion of 'the emergency shut down sequence without interrupting this sequence. However, as soon as the lock-out relay 68 is reset and the control relays 14 and 15 are energized due to the spring 1 being in its 50% speed no load position and the propeller blades being in their 90 position, the energizing circuits for the relays 10, 1I and 12 are opened. The deenergization of the relay 1I completes an energizing circuit for the cam motor 2| so that the cam 20 is then moved to its 30 position. The deenergization of the control relay 12 completes an energizing circuit for the governor magnet II so that the opening spring I2 can effect an opening movement of the movable member 8, but this opening movement is limited by the iiyballs 1, the spring 1 of which is adjusted to its 50% speed no load position. In order to move the spring 1 from this position to or above its 90% speed no load position in another manually operated switch 82 so as to complete an energizing circuit for the springadjusting motor 22 for a suicient length of time to adjust the spring 1 to or above its 90% speed no load position.

In order to prevent rotation of the turbine 3 by the wind when the plant is shut down, I also provide a suitable electrically controlled brake 18 which is arranged to be operated by the closing of a manually controlled switch 19 when the transfer switch 16 is in its non-automatic position and the circuit breaker 41 is open and the propeller blades are in their feathered, or 90 position. Also the energization of the brake 18 is arranged to complete an energizing circuit for the lock-out relay 68 to insure that the relays 68 and 10- cannot be reset as long as the brake is applied.

In order that the angle of the propeller blades may be manually controlled for test purposes while the brake 18 is applied, a control relay 80 is provided which is arranged to be energized by the movement of the transfer switch 16 to its other position if at the same time the relays 1|, 14 and 15 are simultaneously energized. Rielay 80, when energized, permits the spring-adjusting motor 22 to be controlled by the manually controlled switch 82 and the cam motor 2| to be controlled by the manually controlled switch 83.

Y The operation of the control arrangement shown in the drawings is as follows:

It will be assumed rst that the electric system 48 is energized at normal voltage from some other source, not shown, and that the plant has been shut down due to the wind velocity being too low. Under such conditions, the control devices are in the positions in which they are shown in the drawings. The voltage relay 61 is energized so that its contacts 85 are closed. An energizing circuit is completed for the governor magnet through the contacts 86 of the relay 12. The cam 20, which is in its 30 position, maintains the movable member 8 of the governor 6 in such a position that the propeller blades are in their 30 position and the spring 1 is adjusted to above its 90% speed no load position. Therefore, under the assumed conditions, the blade angle position switches |4|1, inclusive; the governor spring position switches 23, 24, and 26; and the cam position switches 28 and 33 are closed, and the blade angle position switch I8; the governor spring position switches 25; and the cam position switches 29-32, inclusive, are open. An energizing circuit is completed for the control relay 6| through the contacts 81 of the power relay 60, and an energizing circuit is completed for a control relay 89 through the auxiliary contacts 90 of the open circuit breaker 41.

When the wind velocity increases above a predetermined value, which is suicient to cause the output of the plant I to exceed a predetermined value, the wind increases the speed of the turbine 3 to a sumcient value to cause the speed switch 36 to close its contacts 9| and complete an energizing circuit for the time relay 31. After being energized for a predetermined time, the relay 31 closes its contacts 92 and completes an energizing circuit for the relay 38 through the contacts 65 of the Voltage relay 61, the resistor 93, the contacts 94 of the relay 1| and the contacts 95 of the lock-out relay 68. The closing of the contacts 96 of the relay 38 completes a shunt circuit around the contacts 85 of the relay 61.`

The closing of the contacts 91 of the relay 38 completes an energizing circuit through the armature 98 and the eld winding 99 of the cam motor 2|, the cam position switch 28 and the contacts |00 of the relay 1| so that the motor 2| operates the cam 20 in such a manner as to effect a decrease in the propeller blade angle. This energizing circuit for the motor 2| is maintained until the cam 20 is moved to its 5 position when the cam position switch 28 is open and the cam position switch 29 is closed. As soon as the cam 20 moves out of its 30 position, the cam position switch 3| is closed. The propeller blade angle follows the position of the cam 20 while the turbine speed is below the setting' of the spring 1', but when the turbine speed increases above this value, the flyballs 1 then control the position of the movable member 8 which, in turn, controls the angle of the propeller blades.

As the turbine speed increases due to the decrease in the blade angle, the voltage of the shunt exciter 39 builds up, and when the turbine speed reaches a predetermined value, the exciter voltage is sufficient to cause the exciter voltage relay 40, which is connected across the exciter terminals by the contacts 11 of the master relay 42, to close its contacts |0|. The closing of the contacts |0| completes an energizing circuit for the time relay 4| through the governor-spring position switch 24, the cam position switch 29, which is closed when the cam 20 reaches its 5 position, the blade angle position switches I 5 and |1 both of which are closed if the blade angle is within the range of 932" and the contacts |02 of the relay 38. After being energized for a predetermined time, the relay 4| closes its contacts |03 and completes an energizing circuit for the master` relay 42 through the contacts 95 of the lock-out relay 68, the contacts 94 of the relay 1|, the contacts |04 of the transfer switch 16, and the contacts |02 of the relay 38. The closing of the contacts |04a of the master relay 42 completes a shunt circuit around the contacts |03 of the relay 4|. This shunt circuit also includes, in parallel, the contacts |05 of the relay 66, and the contacts |06 of the relay 63. The closing of the contacts |01 of the master relay 42 completes an energizing circuit for the operating winding 43 of the iield switch 44 through the contacts |50 of the lock-out relay 68 so that the generator eld winding 45 is excited from the exciter 39. The closing of the auxiliary contacts |08 on the field switch 44 completes an energizing circuit for the control relay 46 through the contacts |09 of the relay 42 and the auxiliary contacts ||0 on the open circuit breaker 41. The closing of the contacts of the relay 46 completes an energizing circuit for the control relay 49 through the contacts |2 of the master relay 42 and the auxiliary contacts ||3 on the open circuit breaker 41. The closing of the contacts ||4 of the relay 49 completes a shunt circuit around the contacts of the relay 46. The closing of the contacts |5 and ||6 of the relay 49 connects the differential frequency responsive means 50 to the system 48 and the generator 2 so that it responds to the frequency diierence thereof. If the frequency of the generator 2 is below the frequency of the system 48, the contacts 52 are closed so as to complete an energizing circuit for the springadjusting motor 22 through the contacts ||1 of the relay 1|, the contacts |66 of the transfer switch 16, the contacts |20 of the relay 63, the governor-spring position switch 26 and the field winding ||8 and the armature ||9 of the motor .the motor 22.

2.2. This. :energizing circuit for the motor 22 causes it .td-adjust :the :spring 1' so as to effect .an increase inthe speed ofthe turbine 3 and the generator 2. If the frequency'of the generator 2 is above .the yfrequency ofthe system 48, the con- .tacts'i'l are closed-solas to'complete anenergizing circuit for thev spring adjusting motor 22 `through the :contacts -t|||-of the relay 1Iy the contacts |66 of lthe transfer switch 1.6, the governor-spring position switch 25a-nd thefield `winding I2| and the armature I8 .offthe motor 22 so that themotor 22 adjusts the espring .1 'insuchafmanneras to effect a Adecreasein the .speed :of the Yturbine 3 and the generator2. v

When ythe frequencies .of the generator 2 and .the system 48 .are the same, .the -contacts 53 and '54 'of-the dilerential frequency responsive means .50a-re simultaneously v.closed so as to complete an Aenergizing-circui-t for y.the time relay ,55. When lthe time yrelay :5.5 closes its contacts |22 and |23, -it .connectsthe `.automatic sy-nchronizer `56 to the generator ..2 and Ithesystem A48.1so that,.as soon as :the proper-phase relation exists thereafter rbetween ,the voltages of lthe l.generator 2 and the system 48, xthe automatic synchronizer 56 closes its "conta-cts 51 and .completes .an energizing circuit .forthe control relay .58 through the auxiliary contacts 42.4 Aon the circuit breaker 41 and the con tacts A|25 `of the .master relay 42. The closing of .the Acontacts 'I 26 .of the control relay 58 cornpletes 4angenergizirig circuit `for the closing coil 59 of Ithe .-circuit breaker 41 to eiect the closing lthereof so that the ,generator 2 is 'connected to the `system 48 `and operates in synchronism therewith.. As soon .as the circuit breaker 41 closes, the .out-of-step relay 64 opens its contacts I5| before the -time relay 89., which is deenergized by the lopen-ing 'of the auxiliary .contacts 90 on the .circuitbreaker 41, :can-.close itscontacts I 52. The contacts |5| and |52 are in series in a shunt `circuit around the Winding of the relay 38.

the relay 4.2.

As soon as the auxiliary contacts |21 `on the circuit breaker .41 are closed, .an energizing circuit is .completed kfor the spring-adjusting motor 22 through the contacts .|.I1 of the relay 1|, the v.

Contact |56 of the transfer switch 16, the contacts |28 of the control `relay 6|, the blade angle position switch I4, the contacts of the relay 53, the governor-spring position switch 26, and the field winding ||8` and the armature IIS of This energizing circuit causes the motor 22 to adjust the spring 1 so as to effect a decrease in the blade angle of the propeller which, in turn, elfects an increase in the output of the plant I until it reaches a value at which the power relay 60 opens its contacts 81 and therebyv effects the deenergization of the control relay 16|. .When the power output of the plant I exceeds the setting of the power relay B0, this relay closes its contacts and completes an energizing circuit vfor a, control relay |3| which, by closing its contacts |32, completes an energizing circuit for the spring-adjusting motor 22 through the contacts ||1 ofv the relay 1|, the

`contact |66 ofthe transfer switch 16, the auxiliary contacts |21 on the closed circuit breaker 41., :the governor-spring position switch 25, and the eld Winding I2| and thearmature |I9 of thernotor22. This energizing circuit causes the motor 22 yto adjust the spring 1 so as to effect an increase in the blade angle of the propeller which, in turn, decreases the output of plant Therefore, during a predetermined range of wind velocities, the power relay i controls the blade .angle of the propeller 4 so Ythat the plantl supplies a predetermined output tothe system 48. It will be ,noted that, as the Wind velocity increases, the blade angle is increased to maintain .the output at the desired value and that, as the wind velocity decreases, the blade angle is decreased to maintain the output at the desired value.

When the wind velocity exceeds a predetermined value, the governing mechanism causes the blade angle to -exceed 28 so that the blade angle position switch A|6 is closed and completes anenergizing circuit `for the -time'relay 62 through the auxiliary contacts |33 von .the closed circuit .breaker 45|. After being energized for a predetermined time, the relay 62 closes its contacts J|34 and completes an energizing circuit `for .the .control relay y63 through the auxiliary contacts `|33 on the .circuit breaker Y41. The closing of thefcontacts |35 of the re1ayf63 completes a shunt .circuit around the vauxiliary --contacts `|21 on the circuit breaker 41 and the contacts |32 of the relay .|3I so that the eld Winding |2| and the armature AI I9 of the motor 22 are energized to cause the ymotor 22 to adjust the spring 1 towards its 100% speed yno load position thereby causing the -blade langle of the propeller to be increased and the output of the `plant I to be decreased. This operating 4circuit for the springadjusting motor 22 also includes the Acontacts I |1 fof the relay 1|, the contact l|66 of the transfer switch 16, and the governor-spring position switch 125. When the blade angle `is increased to 32, or "above, the blade angle position switch I1 in the .circuit of the time relay r4| is `opened so that the .relay -4-I opens its contacts |03 in the original energizing circuit -of the master relay 42. When the power output of the generator 2 decreases below lthesetting vof the power relay so that it closes its contacts |36, an `energizing 'circuit is completed for the-control relay Y66 through the Aauxiliary Icontacts .|33 on :the circuit breaker 41. The closing of the contacts |43 of the .relay 66 completes a shunt circuit around the blade angle position switch I6 in the energizing circuit of the relay 62. The simultaneous opening of the contacts l|06 vof the .relay 63, the contacts |05 of the relay 86 and the contacts |03 of the relay 4| veffects the deenergization-of the master relay 42 which, in turn, by closing its contacts |38, cornpletes an energizing circuit for the trip coil |39 of the' circuit breaker 41 through the contacts |48 of the relay 66 and the auxiliary contacts |4| on the circuit breaker 41 so that the generator 2 is disconnected from the system 48. The opening of the auxiliary contacts IBI lon the circuit breaker 41 interrupts the energizing circuit for the operating winding 43 of the field switch 44 so that the generator field winding 45 is disconnected from the exciter 39. The closing of the contacts |48 of the master relay 42 completes a shunt circuit around the contacts |35 of the relay 63 in the circuit of the eld winding |2| and the armature H8 of the motor 22 so as to insure that the spring 1 is adjusted to a position below its speed no load position.

The opening of the auxiliary contacts L33 on the circuit breaker 41 effects the deenergization of the control relays 62, 63 and 66. Since, however, the speed of the turbine 3, which is being controlled by the flyballs 1, is Suflicient to maintain the speed switch contacts 9| closed under these excessive wind conditions, the relays 31 and 38 are still energized.

When the wind velocity decreases so that the blade angle, as a result of the operation of the tlyballs 1, is again decreased below 32 and the blade angle position switch |1 is closed, the circuit of the master relay 42 is again completed in the manner heretofore described so that the control apparatus operates automatically to place the plant I in service and cause it to supply power to the system 48.

When the plant is in service and the wind velocity decreases below a predetermined value, the output of the plant decreases below the setting of the power relay 65 even though the propeller blade angle is adjusted to its most eflicient angle of The closing of the contacts`|36 of the power relay 65 under these low wind conditions eifects in the manner heretofore described the successive energizations oi the control relays 66, 62 and 63 and the deenergization of the master relay 42 which, in turn, eifects the opening of the circuit breaker 41 and of the field switch 44 and effects the adjustment of the spring 1 to below its 100% speed no load position. If the wind velocity decreases to a sufficiently low value, the speed of the turbine decreases to a suiiiciently low value to cause the speed switch 36 to open its contacts 9| and effect the deenergization of the control relays 31 and 38. The closing of the contacts |44 of the relay 38 under such conditions completes an energizing circuit for the cam motor 2| so that the cam 20 is moved from its 5 position to its 30 position. This energizing circuit for the motor 2| also includes the contacts |45 of thetransfer switch 16, the contacts |46 of the relay 80, the cam position switches 3| and 33 and the field winding |41 and the armature 98 of the motor 2|. The plant I is then in the condition heretofore assumed at the beginning of the description of the operation.

If, while the plant l is in operation, the voltage of the system 48 should for any reason decrease below the drop-out value of the voltage relay 61 so that it closes its contacts |53, a shunt circuit is then completed around the winding of the relay 38. The closing of the contacts |54 of the relay 38 completes an energizing circuit for the trip coil |39 of the circuit breaker 41 through the auxiliary contacts |4| on the circuit breaker. The opening of the contacts |02 of the relay 38 interrupts the energizing circuits of the relays 4| and 42 so that the cam 28 is moved to its 30 position and the spring 1.' is adjusted below its 100% speed no load position in the manner heretofore described. When normal voltage is restored on the system 48, the relay 61 again closes its contacts 85 and the relay 38 then becomes energized and causes the control apparatus to operate automatically to place the plant in service in the manner heretofore described.

If, while the plant is in operation, the generator 2 is pulled out of synchronism for any reason, the out-of-step relay 84 closes its contacts |5| and completes, in series with the contacts |52 of the control relay 89, a shunt circuit around the winding of the relay 38 which then effects the shutting down of the plant in the same manner as when a failure of the system voltage occurs except that, as soon as the circuit breaker 41 is opened, the circuit of the relay 38 is re-established since the shunt circuit around its winding is interrupted by the relay v89 opening its contacts |52. The immediate opening of the contacts |44 of the relay 38 prevents the energizing circuit of the cam motor 2| from being completed for a suflicient length of time to move the cam to its 30 position. The re-energization of the relay 38 then causes the control apparatus to place the plant in operation in the manner heretofore described.

If, while the plant l is in operation, an emergency condition occurs so that the contacts 69 of any one of the emergency condition responsive means are closed, an energizing circuit is completed for the lock-out relay 68. The closing of the contacts |51 of the lock-out relay 68 immediately completes an energizing circuit for the trip coil |39 of the circuit breaker 41 through the auxiliary contacts |4| on the circuit breaker 41 so that the generator 2 is disconnected from the system 48. The opening of the contacts |50 of the lock-out relay 68 interrupts the energizing circuit of the closing coil 43 of the iield switch 44 so that the generator iield winding 45 is disconnected from the exciter 39. The closing of the auxiliary contacts |56 on the circuit breaker 41 completes an energizing circuit for the time relay 1n through the contacts |55 of the lockout relay 68. The immediate closing of the contacts |58 of the relay 10 completes an energizing circuit for the control relay 1|. The closing of the contacts |59 of the relay 1| completes through the contacts |68 of the relay 8|) and the governor-spring position switch 23 an energizing circuit for the field winding |2| and the armature ||9 of the spring-adjusting motor 22 so that the spring 1 is adjusted to its 50% speed no load setting. The closing of the contacts |63 of the relay 1| completes another circuit for the relay 10 through the parallel connected contacts |64 and |65 of the relays 14 and 15 respectively.

After the relay 10 has been energized for a predetermined time, it closes its contacts |6| and completes an energizing circuit for the relay 12. The opening of the contacts 86 of the relay 12 interrupts the energizing circuit of the governor magnet l| so that the closing spring 34 operates the movable member 8 to its shut down position and thereby causes the propeller blades to be moved to their feathered, or 90, position. The closing of the contacts |62 of the relay 12 completes, through the contacts |45 of the transfer switch 16, the contacts |46 of the relay 80 and the cam position switch 33, an energizing .circuit for the field winding |41 and the armature 98 of the cam motor 2| which causes the cam 20 to be moved to its 90 position.

When the propeller blades reach their feathered, or 90, position so that the blade angle po sition switch |8 is closed, an energizing circuit is completed for the control relay 14. When the cam 20 is in its 90 position, the cam position switch 32 completes an energizing circuit for the control relay 15.

In order to restore normal operation of the plant after an emergency shut down thereof, it is necessary to reset the lock-out relay 68 manually. With the lock-out relay 6a in its reset position and the relays 14 and 15 energized, the energizing circuit for the relay 10 is open so that it, in turn, eiiects the deenergization of the relays 1| and 12. The closing of the contacts 86 of the relay 12 re-establishes the energizing circuit the brake.

arredato for the 'governor magnet yll "so that the position 'of the cam` 2:0 controls the position of the movable member 8 'of the governor 6. The closing of the contacts |011 of the relay 1l completes through the cam position switches '3D and 28, a `circuit "for the 'field winding "99 and armature vwinding 98 of lcam motor `2l to move the cam 20 from its "90 :position to its '30 position. In 'this manner the 4equipment-.is returned to its normal starting condition `except that 'the spring l" is still adjusted toits '50% 'speed jno load position. In order to restore the spring 'l' vto above i'ts :90% speed no load setting, which is the position it must be in to 'allow `the 'relay 38 "to be energized,

it is Vnecessaryto move 'the transferA yswitch 16 v fmanually to its 'other position 'and to operate the manually',` controlled 'switch '82, while the 'switch 156 is in :this other position in 'such a manner as to complete 'the energizing 'circuit for the field winding |1'3"'ah'd the armature |19 of the motor 22 for a .suincient length 'of time to allow 'the motor Z2 `to adjust the spring 1" to, or above, its 90% speed no load setting. This energizing circuit 'f'orV the motor 22 'also includes the governorspring contacts `26 Aand the contacts |11 of the relay TI 'The' restoration of the transfer switch '1'6 to th'e position "in which it is shown a'fte'r the spring 1" has vbeen adjusted to its `90% speed no load position re-establishes the necessary connections /for the relay 3i; so that 'it can be energize'd 'to effect 'the starting 'up Yor" the 'plant as soon as the wind velocity is lhigh 'enough to `ef- 'feet 'the energization of the control relay 431.

y"When it is desired vto apply 'the brake '18, an

'emergency shut vdown is effected by' operating the lock-out relay '6% yinfany desired' manner. 'Then the transfer' switch T6 'is moved to its other position, 'and a control switch T9 is closed s'o as to complete an energizing circuit for the brake pletes an energizing circuit for the lock-out 'relay 6'8 so that the resetting oi the lock-'out relay ,7. 681er vthe djee'ner'gi'z'ation of the control relay T0 cannot be effected asvlorrg as the' brake T8 'is applied. The closing ofthe contacts |82 on the brake completes a shunt Vcircuit around the contacts 16'9 o'f the relay yTil 'so that the deener'g'ization of the relay 14 cannot when the transfer switch .1s is moved to its other position while the plant l is shut down and the lock-out relay 68 is in its lock-'out position,

'an energizing circuit is completed for the con`` Atrol relay 8'0 'through the contacts |12 of the relay 1'5, ther contacts |1'3 of the relay 14, the

contacts VM of thefrel'ay TI andthe contacts |15 oi'` the transfer switch 16. The closing of the contacts |16 of the relay 8|!` completes an energizingcircuit for the governor magnet Il, andv the closing of the` contacts |71 of the relay' 80 completes a-shunt circuit around the series connected contacts |112 and |13. The closing of the contacts |18`of the relay 8D renders the mani ually controlled switch 82 operative to control the operation of the spring-adjusting motor 22 so that the setting of the spring 'l' may be adjusted at any desired value for testing purposes. The closing of the contacts |18 also renders the 'effect the yrelease of applied to a particular system and as embody- 'in-g various devices dia-grammatically indicated, changes and modili'cations will be obvious to those skilled in 'the art, 'and I therefore aim in the `appen'cledjclaims to cover all such changes and modifications as fall within the true spirit fand scope of my invention.

What I claim as new and 'desire to secure by Letters Patent of the United States, is:

l. In combination, an alternating current generator 'having a field winding, a iiuid driven prime mover for said generator having a driving propeller which is subjected to iiuid of variable velocity, means for varying 'the blade angle of said propeller, an energized electric system, means operative when the velocity 'of the driving fluid I for said prim-e mover is below a predetermined ,ing of the'l contacts .|11 on vthe brake 18 c'omvalue for causing said blade angle varying means to adjust 'the propeller blade angle to a prede'- termined inefficient value, an exciter 'driven by said prime mover, means responsive to a predetermined 'subnormal speed of 'said prime 'mover ,while the blade angle is at said predetermined -ineiiicient value for `causing said blade angle varying means to ychange the blade angle towards its most ecient value 'thereby eliecting an increase in speed 'of said prime mover, means dependent upon the exciter voltage building up to a predetermined value for connecting said generator to said system.

l2. In combination, an alternating current gen'- 'erator having afield winding, a iiuid driven prime mover for said 'generator having a driving propeller which is subjected 'to fluid of variable 'Velocity, means for varying the blade angle of said propeller, an energized electric system, means operative when the velocity of the Idriving iiuid lfor said prime mover is below a predetermined value for causing said blade angle varying means to adjust the propeller blade angle to a predetermined inefficient value, "an exciter driven by said prime mover, means responsive 'to a predetermined subnormal speed of said prime mover while the blade angle is at said predetermined inefl'icient value for causing said blade angle varying means to change the blade angle towards its most eicie'n't Value thereby effecting an increase in speed of said prime mover, means dependent upon the exciter voltage building up to a predetermined value 'an'd the propeller blade angle being within 'a predetermined range below its most efficient value for 'connecting said generator to said system.

3. In combination, an alternating current generator having a lield winding, a, fluid driven prime mover for said generator having a driving propeller which is subjected to fluid of variable velocity, means for varying `the blade angle of said propeller, an energized electric system, means operative when the velocity of the driving duid for said prime mover is below 'a predetermined "value for causing said blade 'angle varying means said prime mover, means responsive to a prede-v termined subnormal speed of said prime mover while the blade angle is at said predetermined inefficient value for causing said blade angle varying means to change the blade angle towards its most eflicient value thereby effecting an increase in speed of said prime mover, automatic synchronizing means for connecting said generator to said system, and means dependent upon the exciter voltage building up to a predetermined value for rendering said automatic synchronizing means operative.

4. In combination, an alternating current generator having a eld winding, a fluid driven prime mover for said generator having a driving propeller which is subjected to fluid of variable velocity, means for varying the blade angle of said propeller, an energized electric system, means operative when the velocity of the driving fluid for said prime mover is below a predetermined value for causing said blade angle varying means to adjust the propeller blade angle to a predetermined inefficient value, an exciter driven by said prime mover, means responsive to a predetermined subnormal speed of said prime mover while the blade angle is at said predetermined inecient value for causing said blade angle varying means to change the blade angle towards its most eiiicient value thereby effecting an increase in speed of said prime mover, automatic synchronizing means for connecting said generator to said system, and means dependent upon the exciter Voltage building up to a predetermined value and the propeller blade angle being within a predetermined range below its most enicient value for rendering said automatic synchronizing means operative.

5. In combination, an alternating current generator having a field winding, a uid driven prime mover for said generator having a driving propeller which is subjected to fluid of variable velocity, means for varying the blade angle of said propeller, an energized electric system, means operative when the velocity of the driving fluid for said prime mover is below a predetermined value for causing said blade angle varying means to adjust the propeller blade angle to a predetermined inefcient value, an exciter driven by said prime mover, means responsive to a predetermined subnormal speed of said prime mover while the blade angle is vat said predetermined inefficient value for causing said blade angle varying means to change the blade angle towards its most efficient value thereby effecting an increase in speed of said prime mover, means dependent upon the speed of said prime mover increasing to a predetermined value for exciting said generator field winding from said exciter, means responsive to the relative frequencies of said generator and system for controlling said blade angle varying means to decrease the difference` between said frequencies, and means for automatically synchronizing said generator with said system when the frequency difference is below a predetermined value.

6i. In combination, an alternating current system, a generator connected to said system, a`

fluid driven prime mover for said generator having a driving propeller which is subjected to a fluid of variable velocity, means for varying the blade angle of said propeller, means responsive to the power output of said generator for regulating said blade angle varying means to maintain the power output at a predetermined value during a predetermined range of velocities of the driving iiuid, means responsive to a blade angle above a predetermined value for effectingthe operation of said blade angle varying means to decrease the power output of said generator and for preventing said power output responsive means from regulating said blade angle varying means so-as to increase the power output of said generator, and means responsive to the power output of said generator decreasing below a. predetermined value for effecting the disconnection of said generator from said system.

7. In combination, an alternating current system, a generator connected to said system, a fluid driven prime mover for said generator having a driving propeller which is subjected to a fluid of variable velocity, means for varying the blade angle of said propeller, means responsive to the power output of said generator for regulating said blade angle varying means to maintain the power output at a predetermined value during a predetermined range of velocities of the driving fluid, means responsive to a blade angle below a predetermined value for rendering said power output responsive means inoperative to decrease the blade angle further, means responsive to the power output of said generator decreasing below a predetermined value for effecting the disconnection of said generator from said system, and means responsive to a blade angle above a predetermined value for effecting the operation of said blade angle varying means to decrease the power output of said generator.

8. In combination, an alternating current system, a generator connected to said system, a fluid driven prime mover for said generator having a driving propeller which is subjected to a fluid of variable velocity, means for varying the blade angle of said propeller, means responsive to the power output of said generator for regulating said blade angle varying means to maintain the power output at a predetermined value during a predetermined range of velocities of the driving fluid, means responsive to a decrease in the power output of said generator below a predetermined value for effecting the disconnection of said generator from said system, and means for controlling said blade angle'varying means under predetermined high and low velocities of the driving uid so as to decrease the power output of said generator below said last mentioned predetermined value.

9. In combination, an alternating current system, a generator connected to said system, a fluid driven prime mover for said generator having a driving propeller which is subjected to a iiuid of variable velocity, means for varying the blade angle of said propeller, means responsive to the power output of said generator for regulating said blade angle Varying means to maintain the power output at a predetermined value during a predetermined range of velocities of the driving fluid, means responsive to a decrease in the power output of said generator below a predetermined value for effecting the disconnection of said generator from said system, and

means for controlling said blade angle varying means under predetermined high velocities of the driving fluid so as to decrease the power output of said generator below said last mentioned predetermined value.

HERMAN BANY. 

